Open eCommerce can be contrasted to a paint-by-numbers application or drawing. There are many preset and cookie-cutter eCommerce providers out there, many of them quite popular and well regarded. Open-source software offers much more for a business or organization as it allows them to customize anything and make untold decisions to satisfy their unique needs.
Check out my video on the various ways to customize your WooCommerce sites, particularly using the Code Snippets plugin to better organize your PHP customizations. Also, check out my open-source library of WooCommerce code snippet samples.